Maize (Zea mays L.) is one of mankind's most important food crops. Maize is also the only major cultivated plant for which there is no documented wild ancestor and no conclusive evidence concerning its origin, until now. In 1979, a previously unknown relative of maize, a perennial grass at the threshold of extinction, was found in the mountains near Jalisco, Mexico, by Iltis, et al. Science vol. 203, 186-188. This grass, diploid perennial teosinte (Zea diploperennis) is in the same genus as maize, has the same chromosome number (n=10), and hybridizes easily with it.
Tripsacum dactyloides is a more distant relative of corn with a different chromosome number (n=18). It had been known to hybridize with maize but not with teosinte. During the 1984 field season in Bloomington, Ind., I made crosses using pollen from Tripsacum dactyloides onto diploperennis and obtained normal looking fruits. Hybrids were selected for propagation for their drouth resistance, profuse fruit production and because they appeared to be the natural bridge to place Tripsacum genes in teosinte, thereby establishing a link between wild grasses and corn plants as we know them today. Unique propagation of this plant through successive generations by means of cutting has demonstrated that the new plant has not only retained the continuous and abundant production capability but also that its distinguishing characteristics hold true from generation to generation and appeared to be firmly fixed. Propagation has taken place at Bloomington, Ind., Nashville, Tenn., and Raleigh, N.C.